If you’re a cave diver, or if you have ever considered cave diving, you’ve probably spent some time researching the world’s best cave diving sites. Many of the most incredible are a certain type of geologic formation called cenotes. These are not like most other caves or caverns; instead, they connect the earth’s surface to underground rivers and other bodies of water. Here, we’ll take a closer look at how these natural wonders take shape.
Understanding Cenote Formation
Before we get into how cenotes are formed, let’s review a few basics. Most cenotes are located in the Yucatan Peninsula area, while some others are located on or around the Caribbean. The word “cenote” is derived from the Yucatec Mayan word for “well” – and this makes sense, as these caverns were often used as fresh water sources for ancient people. Besides containing clear, sparkling water, they have a well-like shape. Though people could not often easily descend into the cenotes, they often built ladders to access the water inside. These formations are also associated with human sacrifice; archaeologists have discovered ancient remains and grave goods inside some cenotes.
These beautiful formations continue to hold mysterious appeal, and part of the reason we’re so attracted to them has to do with the way they were formed. Long before people began recording history, the Yucatan Peninsula was covered by a vast sea. The remains of the life that sea contained eventually lead to calcium-rich rock formations, which in turn formed huge limestone deposits beneath the earth’s surface. As the centuries passed, rain water seeped through the topsoil above, eroding these deposits. As the erosion deepened, cavities formed and were filled with water. As rocks overhead collapsed, more and more limestone was dissolved, leading to the formation of huge underground spaces. In many cenotes, you can actually see heaps of rubble and even petrified wood left over from eons ago when the collapses took place. This ancient debris is often piled up in the center of the cenote, just beneath the area that is open to the sky above.
Cenotes occur in different sizes. Some are small; others extend for many kilometers, and even connect with one another via underground rivers. Groundwater inside some cenotes is minimal, so they’re more suitable for spelunking than for diving. Some cenotes formed over deeper cave systems, so you’ll find stalactites, stalagmites, and other cavern features inside.
Special terminology is used to describe these caverns and caves. Not only are they classified according to the size and shape of the opening above, those making the classifications also take the body of water contained within the cenote into consideration. Cenotes with cave openings that are smaller than the inner body of water are called pits or jugs. Those with smooth walls that are about the same size as the body of water inside are called cylinders. Those containing shallow bowls-shaped bodies of water are called basins, and those with horizontal connections to the surface are called caves.
There are many outstanding cenote dive sites available. Chac Mool, Taj Mahal, Gran Cenote, and Angelita are just a few you’ll find along the Yucatan. So, get your cave diving certification, and prepare to be amazed. Cenotes are some of the most incredible formations you’ll find anywhere on the planet.